TY - JOUR

T1 - Pion polarizabilities and volume effects in lattice QCD

AU - Hu, Jie

AU - Jiang, Fu Jiun

AU - Tiburzi, Brian C.

PY - 2008/1/9

Y1 - 2008/1/9

N2 - We use chiral perturbation theory to study the extraction of pion electromagnetic polarizabilities from lattice QCD. Chiral extrapolation formulae are derived for partially quenched QCD, and quenched QCD simulations. On a torus, volume dependence of electromagnetic current correlators is complicated by SO(4) breaking, as well as photon zero-mode interactions. We determine finite volume corrections to the Compton scattering tensor of pions. We argue, however, that such results cannot be used to ascertain volume corrections to polarizabilities determined in lattice QCD with background field methods. Connection is lacking because small momentum expansions are not permitted in finite volume. Our argument also applies to form factors. Volume effects for background field calculations of electromagnetic moments cannot be deduced from finite volume form factors.

AB - We use chiral perturbation theory to study the extraction of pion electromagnetic polarizabilities from lattice QCD. Chiral extrapolation formulae are derived for partially quenched QCD, and quenched QCD simulations. On a torus, volume dependence of electromagnetic current correlators is complicated by SO(4) breaking, as well as photon zero-mode interactions. We determine finite volume corrections to the Compton scattering tensor of pions. We argue, however, that such results cannot be used to ascertain volume corrections to polarizabilities determined in lattice QCD with background field methods. Connection is lacking because small momentum expansions are not permitted in finite volume. Our argument also applies to form factors. Volume effects for background field calculations of electromagnetic moments cannot be deduced from finite volume form factors.

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U2 - 10.1103/PhysRevD.77.014502

DO - 10.1103/PhysRevD.77.014502

M3 - Article

AN - SCOPUS:38049152687

VL - 77

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 1

M1 - 014502

ER -